• Best corrected visual acuity at six months and one year
  
• Macular thickness measured by OCT at six months and one year
  
• Median deviation in visual fields at one year
  
• Score on a patient satisfaction scale at six months and one year
  

• Complications associated to each treatment
  

The current gold standard for the treatment of proliferative diabetic retinopathy is panretinal photocoagulation. However, it is a treatment that results in significant discomfort to the patient, causes reduction of visual acuity and visual field impairment. Intravitreal bevacizumab is a novel treatment that reduces intraocular VEGF concentration and therefore inhibits neovascular proliferation, without causing significant disconfort to the patient, nor affecting visual acuity or visual fields (although with other risks associated with intravitreal injection). Making a comparison between both treatments in different patients is difficult because there are other variables that influence the progression of the disease (such as glycemic control or renal insufficiency). Therefore this study is designed using both treatments in the same patient: intravitreal bevacizumab in one eye, compared to panretinal photocoagulation in the contralateral eye, and evaluating visual acuity, visual fields, fluorescein angiography, optic coherence tomography of the macula, and patient discomfort, in a one-year follow-up.